High Strength Wrapping Material Containing Extracted Tobacco

ABSTRACT

A wrapping material for an aerosol producing product is disclosed that contains extracted tobacco material combined with strength building fibers. The strength building fibers are refined and optionally bleached bast fibers. In one aspect, the bast fibers can be hemp fibers. The wrapping material can contain the extracted tobacco material in amounts greater than  40 % by weight.

RELATED APPLICATIONS

The present application is based upon and claims priority to U.S.Provisional Patent Application Ser. No. 63/155,518, having a filing dateof Mar. 2, 2021, and which is incorporated herein by reference.

BACKGROUND

Various different aerosol generating products exist that generate anaerosol for enjoyment by a user. Such products include, for instance,smoking articles, heat but not burn sticks, and the like. Aerosolgenerating products typically include an aerosol generating filler inthe shape of a rod that is covered by an outer wrapper.

Traditionally, outer wrappers for aerosol generating products have beenmade from papermaking fibers, such as pulp fibers. The use ofpapermaking fibers, for instance, provides a wrapper that has sufficientstrength to be fed through high speed machinery used to produce theaerosol generating products.

Although papermaking fibers provide various advantages when producingwrapping materials for aerosol generating products, such as smokingarticles, papermaking fibers can negatively affect the overall taste ofthe product. Thus, in the past, those skilled in the art have attemptedto incorporate tobacco materials into wrapping papers. Incorporatingsignificant amounts of tobacco material into wrapping papers, however,negatively impacts the strength of the product. In particular, wrappingpapers made in the past containing substantial amounts of tobaccomaterial have not displayed sufficient strength to be used in high speedmachines, such as cigarette making machines.

In view of the above, a need exists for a wrapping material containingsubstantial amounts of tobacco that has sufficient strength for use inconstructing aerosol generating products.

SUMMARY

In general, the present disclosure is directed to a wrapping materialfor an aerosol generating product that is made from a tobacco material.More particularly, the present disclosure is directed to a high strengthwrapping material containing substantial amounts of a tobacco material.The wrapping material of the present disclosure can be used to produceall different types of products, including cigarettes and other smokingarticles, heat but not burn sticks, and the like.

In one embodiment, for example, the present disclosure is directed to awrapping material for covering an aerosol producing filler. The wrappingmaterial includes a web comprising at least about 40% by weight of anextracted tobacco material. The extracted tobacco material is blendedwith strength building fibers. The strength building fibers compriserefined bast fibers. The refined bast fibers have an average fiberlength of less than about 4 mm. The wrapping material has a basis weightof from about 15 gsm to about 45 gsm.

In certain aspects, the web can contain at least about 50% by weight,such as at least about 60% by weight, such as at least about 70% byweight, such as at least about 80% by weight extracted tobacco material.The tobacco material is extracted such that the tobacco material and/orthe web has a water soluble content of less than about 20% by weight,such as less than about 17% by weight, such as less than about 15% byweight, such as less than about 12% by weight, such as less than about10% by weight, such as less than about 8% by weight. The refined bastfibers can comprise hemp fibers and can be present in the web in anamount greater than about 10% by weight, such as in an amount greaterthan about 12% by weight, such as in an amount greater than about 14% byweight, such as in an amount greater than about 16% by weight. In oneaspect, the refined bast fibers are also bleached.

In accordance with the present disclosure, the wrapping material canhave a tensile strength when measured according to ASTM Test D828-97 ofgreater than about 2,100 cN/30 mm, such as greater than about 2,200cN/30 mm, such as greater than about 2,300 cN/30 mm, such as greaterthan about 2,400 cN/30 mm, and generally less than about 3,400 cN/30 mm.The wrapping material can also have a stretch of greater than about 1%,such as greater than about 1.2%, such as greater than about 1.5% whenmeasured according to ISO Test 1924 (2008).

Optionally, the wrapping material can also contain wood pulp fibers. Thewood pulp fibers, for instance, can be softwood fibers, hardwood fibers,or mixtures thereof. Wood pulp fibers can be present in the web in anamount up to about 10% by weight, and generally in an amount less thanabout 8% by weight, such as in an amount less than about 6% by weight.

In one aspect, the tobacco material contained in the wrapping materialhas been fed through an extraction process for removing water solublecomponents and has also been refined. In one embodiment, however, thetobacco material has not been fed through a pulping process, whichrefers to combining the tobacco material with a base, such as sodiumhydroxide, and cooked in a digester. Of particular advantage, the use ofthe refined bast fibers allows for the use of extracted but non-pulpedtobacco fibers while still providing sufficient strength and formationproperties.

In one aspect, the wrapping material has a basis weight of from about 25gsm to about 38 gsm. The wrapping material can have a permeability offrom about 5 Coresta to about 80 Coresta, such as from about 8 Corestato about 38 Coresta. The wrapping material can optionally contain afiller. For example, in one embodiment, the wrapping material containsno filler particles. Alternatively, filler particles can be present inthe wrapping material in an amount from about 0.5% by weight to about30% by weight, such as from about 1% by weight to about 12% by weight.

In one aspect, the wrapping material can be treated with a burn controlagent for better control of the burn properties. For instance, the burncontrol agent can comprise a salt of a carboxylic acid, such as acitrate or a succinate. The burn control agent can be present on thewrapping material in an amount from about 0.3% by weight to about 3% byweight, such as in an amount from about 1% by weight to about 2% byweight.

The wrapping material can also be treated with a humectant and/or a gum.The humectant, for instance, can comprise glycerol, propylene glycol, ormixtures thereof. The gum, on the other hand, can comprise guar gum, analginate, carboxymethyl cellulose, or mixtures thereof. The gum can bepresent on the wrapping material in an amount from about 0.1% by weightto about 2% by weight.

When used in smoking articles, the wrapping material can also optionallyinclude a plurality of discrete reduced ignition areas spaced along afirst direction of the wrapping material. The reduced ignition areas canhave a diffusivity of less than about 0.5 cm/s at 23° C. The pluralityof reduced ignition areas can be formed by applying a reduced ignitioncomposition to the web. The reduced ignition composition, for instance,can comprise cellulose fibers, a film forming material, or mixturesthereof.

Other features and aspects of the present disclosure are discussed ingreater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present disclosure is set forthmore particularly in the remainder of the specification, includingreference to the accompanying figures, in which:

FIG. 1 is a perspective view of one embodiment of an aerosol generatingproduct incorporating the wrapping material of the present disclosure;and

FIG. 2 is an exploded view of the aerosol generating product illustratedin FIG. 1.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present invention.

Definitions

As used herein, an “aerosol generating material” is meant to includeboth a combustible material that undergoes combustion in a smokingarticle and to an aerosol-forming material that is heated but notcombusted to form an inhalable aerosol. Combustible smoking articles caninclude cigarettes, cigarillos and cigars, pre-rolled cones etc. In acigarette, the aerosol generating material is generally surrounded by awrapping material to form a smokable rod. Aerosol generating devices forgenerating an aerosol include, for instance, devices in which an aerosolis generated by electrical heating or by the transfer of heat from acombustible fuel element or heat source to heat but not burn the aerosolgenerating material, which releases volatile compounds. As the releasedcompounds cool, they condense to form an aerosol that is inhaled by theconsumer.

As used herein, “extracted tobacco fibers” refers to tobacco fibers thathave been subjected to an extraction process in which the tobacco hasbeen contacted with an aqueous solution to remove greater than 40%, suchas greater than 50%, such as greater than 60%, such as greater than 70%,such as greater than 75% of the water soluble components contained inthe tobacco. The extraction process is from a delignification processand from a bleaching treatment.

As used herein, “delignified” cellulosic fibers refers to fibers thathave been subjected to a pulping or delignification process by which thecellulose fibers are separated from the plant material through chemicalmeans, mechanical means, or through a combination of chemical andmechanical means.

As used herein, the term “refine” is used to mean that the plantmaterial is subjected to a mechanical treatment that modifies the fibersof the material so that they are better suited to forming a fibroussheet or substrate. Refining can be accomplished using a conical refineror a disks refiner or a Valley beater. The mechanical process exerts anabrasive and bruising action on the plant material such that the plantmaterial is defibrillated. Refining is a different process thandelignification and pulping.

As used herein, the “amount of water soluble extracts” present in asubstrate or reconstituted plant material or in an aerosol-generatingmaterial is determined by taking 5 grams of a sample in boilingdistilled water for 10 minutes to obtain an extract containing watersoluble components. The weight of dry matter of the extract that issoluble in the solvent is calculated by the difference between the dryweight of the sample and the dry weight of the sample after extraction.The difference in dry weight is then used to determine the percentage ofwater soluble extracts in the sample.

DETAILED DESCRIPTION

It is to be understood by one of ordinary skill in the art that thepresent discussion is a description of exemplary embodiments only and isnot intended as limiting the broader aspects of the present disclosure.

The present disclosure is generally directed to a wrapping material foran aerosol generating product that is formed from a web that includesextracted tobacco fibers combined with strength building fibers. Thestrength building fibers comprise refined bast fibers, such as hempfibers. In accordance with the present disclosure, the wrapping materialcan contain a tobacco material in amounts greater than 40% by weight andstill have sufficient strength and other properties needed for massproducing aerosol generating products, such as smoking articles, heatbut not burn sticks, and the like.

The high amount of tobacco fibers contained in the wrapping materialcreates a natural and pleasant tobacco taste when consumed in an aerosolproducing product. In addition, the tobacco material is extracted byremoving water soluble components. Removing the water soluble componentscan remove undesirable components. In one aspect, the water solublecomponents can be optionally concentrated and/or filtered and reapplied.In another aspect, flavorants can be applied to the wrapping material.Due to the mechanical properties, the wrapping material of the presentdisclosure also has great runnability characteristics on conventionalcigarette making machines. The wrapping material of the presentdisclosure can be used to produce all different types of aerosolgenerating products, such as cigarettes, cigarillos, and the like. Thewrapping material can also be combined with substantial amounts of ahumectant for use in heat but not burn applications.

In addition to the above advantages, the wrapping material of thepresent disclosure also has excellent aesthetic properties. Forinstance, the wrapping material can have a visual association with atobacco identity due to the great amounts of tobacco material that arecontained in the product. In addition, the wrapping material can betreated with a coloring agent, such as a dye, in order to furtherenhance a natural tobacco look.

As described above, the wrapping material of the present disclosureincludes a blend of an extracted tobacco material and strength buildingfibers. Optionally, the wrapping material may also contain pulp fibersand/or filler particles.

The tobacco materials that can be used to produce the wrapping materialcan include any suitable type of tobacco furnish. The tobacco furnish,for instance, can contain tobacco stems, such as flue-cured stems,leaves, fines, and/or other tobacco by-products. In accordance with thepresent disclosure, the tobacco material can be subjected to anextraction process for removing water soluble components. Specifically,the compounds naturally present in the tobacco material that are solublein a solvent, such as water, may give rise to problems, such as duringmaking of the wrapping material or later during the making of aerosolgenerating products. Consequently, the tobacco materials incorporatedinto the wrapping material are preferably subjected to an extractionprocess. The extraction process may include placing the tobaccomaterials in water and allowing the water soluble portions to beextracted into the water. In an alternative embodiment, various solventsthat are water-miscible, such as alcohols (e.g., ethanol), and/orsuitable oils and fats, can be combined with water to form an aqueoussolvent. The water content of the aqueous solvent can, in someinstances, be greater than about 50% by weight, such as greater thanabout 90% by weight of the solvent. Deionized water, distilled water, ortap water may be employed. The amount of the solvent in the tobaccomaterial suspension can vary widely, but is generally added in an amountfrom about 50% by weight to about 99% by weight, such as from about 60%by weight to about 95% by weight, and, in one aspect, from about 75% byweight to about 90% by weight of the suspension. In one embodiment, thesolvent may be heated prior to or during contact with the tobaccomaterials. For example, in one aspect, the extraction solution may be ahot aqueous solution.

The tobacco material and solvent can optionally be agitated by stirring,shaking, or otherwise mixing the suspension in order to increase therate of solubilization. Typically, the process can be carried out forabout ten minutes to about six hours. Process temperatures may rangefrom about 10° C. to about 100° C., such as from about 23° C. to about80° C. In one aspect, the temperature of the suspension can be fromabout 40° C. to about 80° C.

After the tobacco materials are soaked and optionally agitated, theinsoluble portion of the tobacco material can be mechanically separatedfrom the soluble portion of the tobacco material using a press or acentrifuge or any other suitable device or method. Once the solublefraction is separated from the insoluble fraction, the soluble fractioncan be discarded or further processed, such as by being concentrated.The soluble fraction can be concentrated using any known type ofconcentrator, such as a vacuum evaporator. In some applications, thewater soluble fraction can be discarded or used in other processes.However, if desired, a portion or all of the soluble fraction can beconcentrated and reapplied to the web formed from the extracted tobaccomaterials.

The extraction process carried out on the tobacco material removessoluble compounds which facilitates the processing of the tobaccomaterial into a web. The extraction process can also be used to removeundesired compounds. For instance, through the extraction process,various different components, such as nitrosamines, may be removed fromthe tobacco material. The extraction process can also remove, ifdesired, nicotine.

The resulting water insoluble, extracted tobacco material is generallyin an unrefined state. The tobacco material can comprise particles andfibers. In one embodiment, the insoluble and extracted tobacco materialcan optionally be subjected to a refining process. For instance, theextracted tobacco material can be fed through any suitable refiningdevice, such as a conical refiner or a disk refiner. Other refiningdevices that may be used include a beater, such as a Valley beater.Refining can occur while the tobacco materials are moist or after beingcombined with water. For instance, in one embodiment, refining can occurwhile the tobacco material is at a consistency of less than about 10%,such as less than about 5%, such as less than about 3%.

The extracted and refined tobacco materials, in one aspect, can containa relatively low amount of water soluble components. For instance, theextracted tobacco material can contain water soluble components in anamount less than about 30% by weight, such as in an amount less thanabout 20% by weight, such as in an amount less than about 17% by weight,such as in an amount less than about 15% by weight, such as in an amountless than about 12% by weight, such as in an amount less than about 10%by weight, such as in an amount less than about 8% by weight, such as inan amount less than about 6% by weight and generally greater than about2% by weight. As described above, optionally the water solublecomponents can be concentrated, otherwise treated, and reapplied to theweb formed from the tobacco material. In one preferred embodiment,however, the water soluble components are not reapplied to the extractedtobacco materials.

In accordance with the present disclosure, the extracted tobaccomaterial or tobacco fibers are combined with strength building fibers,particularly refined bast fibers. The extracted tobacco fibers can benon-pulped meaning that the fibers have not been fed through a pulpingprocess in which the fibers are combined with an alkaline material(Kraft process) or an acid material (Sulfite process) and cooked in adigester. The strength building fibers, on the other hand, can be pulpedor delignified. In one aspect, the extracted tobacco material can becombined with water or an aqueous solution to form a slurry. Thestrength building fibers, such as delignified cellulosic bast fibers,can be combined with the tobacco material in forming the slurry. Thefiber slurry is then used to form a continuous web that has thecharacteristics of paper. For example, in one embodiment, the fiberslurry can be fed to a papermaking process that can include a formingwire, gravity drain, suction drain, a felt press, and a dryer, such as aYankee dryer, a drum dryer or the like. In one aspect, the fiber slurryis formed into a continuous sheet on a Fourdrinier table.

The fiber slurry containing the extracted tobacco material and thestrength building fibers, for instance, can be laid onto a porousforming surface and formed into a sheet. Excess water can be removed bya gravity drain and/or a suction drain. In addition, various presses canbe used to facilitate water removal. The formed sheet can be dried andfurther treated.

As described above, the strength building fibers are refined bastfibers. The bast fibers can also be pulped or delignified and/orbleached. Examples of bast fibers that may be used in the presentdisclosure include hemp fibers, flax fibers, abaca fibers, ramie fibers,cotton fibers, bamboo fibers, esparto fibers, and mixtures thereof. Thebast fibers can be highly refined using, for instance, a Dutch ValleyBeater. In one particular embodiment, the bast fibers are hemp fibersalone or in combination with other bast fibers.

As described above, the bast fibers can be highly refined. The bastfibers can have an average fiber length of generally greater than about0.5 mm, such as greater than about 0.8 mm, such as greater than about 1mm, such as greater than about 1.2 mm, such as greater than about 1.5mm. The average fiber length of the refined bast fibers is generallyless than about 4 mm, such as less than about 3.6 mm, such as less thanabout 3.3 mm, such as less than about 3 mm, such as less than about 2.8mm, such as less than about 2.5 mm, such as less than about 2.3 mm, suchas less than about 2.1 mm. In one particular aspect, the bast fibers canbe delignified hemp fibers having an average fiber length of from about1.5 mm to about 2 mm.

Optionally, the web formed according to the present disclosure can alsocontain wood pulp fibers and/or botanical fibers. The wood pulp fibers,for instance, can comprise delignified fibers, such as softwood fibers,hardwood fibers, or mixtures thereof.

The extracted tobacco material, strength building fibers, and optionallywood pulp fibers can be combined together in order to form a web. In oneaspect, the fibers are all combined together in an aqueous suspensionand used to form a web through a wetlaid process. In this manner, asubstantially homogeneous fiber distribution is achieved. The amount ofeach fiber contained in the resulting web can vary. In general, the webformed according to the present disclosure contains extracted tobaccomaterial in an amount greater than about 40% by weight and in an amountup to about 90% by weight, including all increments of 1% by weighttherebetween. For example, the extracted tobacco material can becontained in the web in an amount greater than about 45% by weight, suchas in an amount greater than about 50% by weight, such as in an amountgreater than about 55% by weight, such as in an amount greater thanabout 60% by weight, such as in an amount greater than about 65% byweight, such as in an amount greater than about 70% by weight, such asin an amount greater than about 75% by weight, such as in an amountgreater than about 80% by weight, such as in an amount greater thanabout 85% by weight. The extracted tobacco material can be contained inthe web in an amount less than about 80% by weight, such as in an amountless than about 75% by weight, such as in an amount less than about 70%by weight.

The strength building fibers can be present in the web generally in anamount up to about 50% by weight. The strength building fibers aregenerally present in the web in an amount greater than about 5% byweight, such as in an amount greater than about 10% by weight, such asin an amount greater than about 15% by weight, such as in an amountgreater than about 17% by weight, such as in an amount greater thanabout 20% by weight, such as in an amount greater than about 23% byweight, such as in an amount greater than about 25% by weight, such asin an amount greater than about 28% by weight, such as in an amountgreater than about 30% by weight. The strength building fibers aregenerally present in an amount less than about 35% by weight, such as inan amount less than about 30% by weight, such as in an amount less thanabout 25% by weight, such as in an amount less than about 20% by weight.As described above, in one embodiment, the strength building fibers arerefined hemp fibers.

Wood pulp fibers can optionally be present in the web. In one aspect,for instance, the web can be produced without any wood pulp fibers. Inother embodiments, however, the wood pulp fibers can be present in anamount up to about 12% by weight, such as in an amount up to about 10%by weight, such as in an amount up to about 8% by weight. The wood pulpfibers can generally be present in an amount greater than about 2% byweight, such as in an amount greater than about 5% by weight, such as inan amount greater than about 7% by weight. In one particular aspect, thewood pulp fibers and the extracted tobacco fibers can be preblended andthen later combined with the strength building fibers. For instance, theextracted tobacco material and wood pulp fibers can be preblended at aweight ratio of from about 85:15 to about 95:5 and then combined withthe strength building fibers.

In one aspect, the extracted tobacco material, strength building fibers,and optionally wood pulp fibers can be combined together and refinedtogether prior to forming the web. Alternatively, each fiber can berefined separately. In still another embodiment, each fiber can berefined separately, combined together, and then refined a furtheramount.

Optionally, the web can also contain filler particles. Filler particlesthat can be used include carbonate particles, oxide particles, andmixtures thereof. Particular filler particles include, for instance,calcium carbonate particles, magnesium oxide particles and mixturesthereof. Filler particles can be present in the web generally in anamount from about 0.5% by weight to about 30% by weight, including allincrements of 0.5% therebetween. For instance, filler particles can bepresent in an amount greater than about 1% by weight, such as in anamount greater than about 2% by weight, such as in an amount greaterthan about 5% by weight, and generally in an amount less than about 25%by weight, such as in an amount less than about 20% by weight, such asin an amount less than about 15% by weight, such as in an amount lessthan about 12% by weight, such as in an amount less than about 8% byweight. In one aspect, filler particles can be present in an amount fromabout 0.5% by weight to about 5% by weight, such as from about 0.5% byweight to about 2% by weight when the web contains extracted tobaccomaterial in an amount of about 50% by weight or greater. In anotheraspect, the web can be completely free of any filler particles,particularly alumina particles or other aluminum-containing fillerparticles.

Although the web may contain filler particles, in one aspect, the web isprimarily made from fibers, such as tobacco fibers, strength buildingfibers, and optionally pulp fibers. For instance, the fiber content ofthe web can be greater than about 90% by weight, such as greater thanabout 92% by weight, such as greater than about 95% by weight, andgenerally less than about 99% by weight, such as less than about 98% byweight, such as less than about 97% by weight.

As described above, the extracted tobacco material is combined with thestrength building fibers and formed into a web, in one aspect, using awet lay process. Webs made according to the present disclosure have goodstrength, are smooth, and can be formed to have optimum basis weight andpermeability. Thus, a wrapping material made according to the presentdisclosure is capable of withstanding a papermaking process as well asthe mechanical stress of mass production of smoking articles, while alsohaving improved sensory characteristics and burn properties.

For instance, wrapping materials made in accordance with the presentdisclosure have excellent mechanical characteristics and have a verydesirable and aesthetic appearance. In general, the wrapping materialhas a basis weight of greater than about 15 gsm, such as greater thanabout 18 gsm, such as greater than about 20 gsm, such as greater thanabout 23 gsm, such as greater than about 25 gsm. The basis weight of thewrapping material is generally less than about 100 gsm, such as lessthan about 50 gsm, such as less than about 45 gsm, such as less thanabout 43 gsm, such as less than about 40 gsm, such as less than about 38gsm, or any ranges therebetween. Within the above basis weights, thewrapping material is very strong and can exhibit a tensile strength ofgreater than about 2,100 cN/30 mm, such as greater than about 2,200cN/30 mm, such as greater than about 2,300 cN/30 mm, such as greaterthan about 2,400 cN/30 mm, and generally less than about 4,000 cN/30 mm.Tensile strength can be measured using ASTM Test D828-97.

In addition to relatively high tensile strength, the wrapping materialcan also have excellent stretch properties. For instance, the wrappingmaterial can display a stretch of greater than about 1%, such as greaterthan about 1.2%, such as greater than about 1.4%. The stretch of thewrapper is generally less than about 4%, such as less than about 2%.

The wrapping material according to the present disclosure may also havea permeability that facilitates suitable smoking properties, such asgood mainstream smoke control or good smoking comfort. For instance, thewrapping material according to the present disclosure may have apermeability measured in Coresta units of from below detectable limits(i.e. 0 Coresta) to about 100 Coresta, such as from about 5 Coresta toabout 80 Coresta, such as from about 8 Coresta to about 38 Coresta, orany ranges therebetween. The permeability can be greater than about 8Coresta, such as greater than about 10 Coresta, such as greater thanabout 15 Coresta, such as greater than about 20 Coresta, such as greaterthan about 25 Coresta, and generally less than about 65 Coresta, such asless than about 55 Coresta, such as less than about 45 Coresta. Theabove permeability characteristics refer to the inherent permeability ofthe paper meaning the permeability of the paper without subjecting thepaper to any treatments, such as perforating, that changes thepermeability characteristics.

While the wrapping material according to the present disclosure maynaturally or inherently have a desired permeability, in one embodiment,it may be desirable to also perforate the wrapping material afterformation. Perforation may be performed as known in the art, and thenumber and size of the perforations may be selected as needed for thedesired application.

In addition to the above physical properties, the wrapping material madein accordance with the present disclosure can exhibit a distinct naturalappearance with natural speckling and/or coloration from the one or moretobacco fibers or particles. Optionally, the wrapping material may beformulated with pigments (natural or synthetic) to adjust its finalcoloration. For instance, a coloring agent, such as a dye, may beapplied to the fibers in a head box in an aqueous solution or applied tothe web using a size press during formation of the web and prior todrying. In one aspect, for instance, one or more coloring agents may beused that provide the web with a natural tobacco color, such as a browncolor.

Furthermore, in addition to having a natural appearance, the wrappingmaterial according to the present disclosure may also have a pleasanttexture. The wrapping material can have a relatively rough surface,which emphasizes its natural appearance or can be further calendared toprovide a smoother feeling.

The wrapping material of the present disclosure may also be used toproduce smoking articles having better taste and sensory properties. Forinstance, the wrapping material of the present disclosure produces aless papery taste than conventional smoking papers. Instead, a pleasantneutral or distinct, natural tobacco taste has been observed, even whenthe wrapping material contains cellulosic strength building fibers. Inone aspect, one or more flavorants can also be applied to the fibersand/or to the web during or after formation of the web. Flavorants caninclude sweetening agents, terpenes or the like.

Wrapping materials made according to the present disclosure can beincorporated into all different types of smoking articles andaerosol-generating products. For illustrative purposes only, one suchsmoking article is shown in FIGS. 1 and 2. As shown, the smoking article10 includes a smokable column 12. The smokable column 12, for instance,can be in the shape of a cylindrical rod comprising an aerosol producingfiller. The smoking article 10 may also include a wrapping material 100that defines an outer circumferential surface 16 when wrapped around thesmokable column 12. The wrapping material 100 can include overlappingedges 114 and 116 that are sealed together. The article 10 may alsoinclude a filter 26 that may be enclosed by a tipping paper, however,depending upon the smokable column material, a filter may be optional oromitted.

The smoking article shown in FIGS. 1 and 2 can be a cigarette, acigarillo, a little cigar, or the like. Alternatively, the article can aheat but not burn stick.

In still another aspect, the wrapping material can be formulated as abooklet of individual wrapping materials. The individual wrappingmaterials, for instance, can be adhered to each other using a smokableor edible adhesive. The book of wrapping materials can be used inroll-your-own applications where a user would use the wrapping materialto make his or her own smoking article or heat but not burn stick.

In one aspect, the wrapping material of the present disclosure can betreated with a gum. In one aspect, the gum can serve as an adhesive. Inone embodiment, the gum may include alginates, arabic gum, guar gum,pectin, polyvinyl alcohol, polyvinyl acetate, cellulose derivatives suchas ethyl cellulose, methyl cellulose, and carboxymethyl cellulose,starch, starch derivatives, and the like.

In one particular embodiment, the gum may include an Arabic gum,cellulose, and/or cellulose derivatives. In one embodiment, cellulosederivatives include carboxy methyl cellulose (CMC), methylcellulose(CM), hydroxypropyl methyl cellulose (HPMC).

Regardless of the gum used, the gum may be present on the wrappingmaterial or web in an amount of from about 0.1% to about 15% by weight,such as from about 2% to about 5% by weight. In one embodiment, the gummay be applied using direct or indirect coating methods. The gum can beapplied via a spray, such as a microspray, or may be otherwise appliedso as to form a thin coating over the desired area using, for instance,gravure printing.

In one embodiment, smoking articles made according to the presentdisclosure can also have reduced ignition propensity characteristics.For instance, the wrapping material of the present disclosure may beused as an outer wrapper of the smoking article and can have inherentreduced ignition properties or can optionally include a plurality ofdiscrete reduced ignition areas spaced in the axial direction of thesmoking article. For instance, in one embodiment, the discrete reducedignition areas may be in the form of circular bands. The bands can havea width so that oxygen is limited to the burning coal for a sufficientlength or period of time to extinguish the coal if the smoking articlewere left in a static burn condition. The bands, for instance, can havea width of generally greater than about 3 mm, such as greater than about4 mm, such as greater than about 5 mm, and generally less than about 10mm, such as less than about 8 mm, such as less than about 7 mm.

The spacing between the reduced ignition areas can also vary dependingupon a number of variables. The spacing should not be so great that thecigarette burns for a sufficient length of time to ignite a substratebefore the coal burns into a reduced ignition area. The spacing alsoaffects the thermal inertia of the burning coal, or the ability of thecoal to burn through the reduced ignition areas withoutself-extinguishing. In general, the band spacing should be greater thanabout 5 mm, such as greater than about 10 mm, such as greater than about15 mm, and generally less than about 50 mm, such as less than about 40mm, such as less than about 30 mm. Each smoking article can contain fromabout 1 to about 3 bands.

In general, any suitable ignition reducing composition can be applied tothe outer wrapper/wrapping material of the smoking article. In oneembodiment, for instance, the ignition reducing composition contains afilm-forming material. For example, film-forming materials that can beused in accordance with the present invention include alginates, guargum, pectin, polyvinyl alcohol, polyvinyl acetate, cellulose derivativessuch as ethyl cellulose, methyl cellulose, and carboxymethyl cellulose,starch, starch derivatives, and the like.

In one particular embodiment, the film-forming material may comprise analginate, alone or in combination with starch. In general, an alginateis a derivative of an acidic polysaccaride or gum which occurs as theinsoluble mixed calcium, sodium, potassium and magnesium salt in thePhaeophyceae brown seaweeds. Generally speaking, these derivatives arecalcium, sodium, potassium, and/or magnesium salts of high molecularweight polysaccarides composed of varying proportions of D-mannuronicacid and L-guluronic acid. Exemplary salts or derivatives of alginicacid include ammonium alginate, potassium alginate, sodium alginate,propylene glycol alginate, and/or mixtures thereof.

In one embodiment, a relatively low molecular weight alginate may beused. For example, the alginates may have a viscosity of less than about500 cP when contained in a 3% by weight aqueous solution at 25° C. Moreparticularly, the alginates may have a viscosity of less than 250 cP atthe above conditions, particularly less than 100 cP, and in oneembodiment at a viscosity of about 20-60 cP. As used herein, viscosityis determined by a Brookfield LVF Viscometer with a suitable spindleaccording to the viscosity. At the above lower viscosity levels,alginate compositions can be formed at a higher solids content, but yetat a low enough solution viscosity to permit the application of thecomposition to a paper wrapper using conventional techniques. Forexample, the solids content of an alginate solution made in accordancewith the present invention can be greater than about 6%, particularlygreater than about 10%, and more particularly from about 10% to about20% by weight.

At the above solids levels, alginate compositions used in accordancewith the present invention can have a solution viscosity of greater thanabout 250 cP, particularly greater than about 500 cP, more particularlygreater than about 800 cP, and in one embodiment at a viscosity ofgreater than about 1,000 cP at 25° C. In general, the solution viscosityof the alginate film-forming composition can be adjusted depending uponthe manner in which the composition is being applied to the wrapper. Forinstance, the solution viscosity of the composition can be adjusteddepending upon whether or not the composition is being sprayed onto thepaper or printed onto the paper.

In other embodiments, it should also be understood that depending uponthe application a relatively high molecular weight alginate may be used.For example, the alginate may have a viscosity of greater than about 500cP when contained in a 3% by weight aqueous solution at 25° C.

In addition to the film-forming material, the reduced ignitioncomposition applied to the wrapper can contain various otheringredients.

For instance, in one embodiment, a filler can be contained within thecomposition. The filler can be, for instance, calcium carbonate, calciumchloride, calcium lactate, calcium gluconate, and the like. In additionto calcium compounds, other various particles may be used includingmagnesium compounds such as magnesium oxide, clay particles, and thelike.

The ignition reducing composition, in one embodiment, can be waterbased. In particular, the ignition reducing composition may comprise anaqueous dispersion or aqueous solution. Alternatively, the ignitionreducing composition prior to being applied to the paper wrapper maycomprise a non-aqueous solution or dispersion. In this embodiment, forinstance, an alcohol may be present for applying the composition to thewrapper.

As opposed to a film-forming composition, the ignition reducingcomposition may also comprise a cellulose slurry (a type of dispersion).As used herein, a slurry containing papermaking materials is not afilm-forming composition. The cellulose slurry applied to the papersubstrate may comprise fibrous cellulose, one or more fillers, and/orcellulose particles. As used herein, cellulose fibers and celluloseparticles are to be differentiated from derivatized cellulose such ascarboxymethyl cellulose. Cellulose fibers and cellulose particles, forinstance, are not water soluble. In one embodiment, the cellulose slurryapplied to the paper substrate may comprise microcrystalline cellulose.

Once the ignition reducing composition is formulated, the compositioncan be applied to a paper wrapper in discrete areas. The manner in whichthe composition is applied to the paper wrapper can vary. For example,the composition can be sprayed, brushed, applied with a moving orifice,or printed onto the wrapper. To form a treated area, the composition canbe applied in a single pass or in a multiple pass operation. Forinstance, the composition can be applied to the wrapping paper insuccessive steps in order to form areas on the paper having reducedignition proclivity. In general, during a multiple pass process, thetreated areas can be formed by applying the composition during fromabout 2 to about 8 passes.

The amount of reduced ignition composition applied to the wrapper canalso vary. For instance, the composition can be applied to the wrapperin an amount less than about 15% by weight, such as less than about 10%by weight, such as less than about 8% by weight. In general, thecomposition is applied in an amount greater than 1% by weight based uponthe weight of the composition within the reduced ignition areas.

As used herein, the above weight percentages are based on the areatreated with the chemical components. In other words, the weightpercentages above for the reduced ignition composition is the amountapplied within the treated areas as opposed to the total amount appliedover the entire surface of the wrapper.

Through the process of the present disclosure, reduced ignition areascan be produced having a relatively high permeability while also havinga relatively low diffusivity. For instance, the reduced ignition areascan have a permeability greater than 10 CORESTA while still beingcapable of producing smoking articles that pass ASTM Test E2187-09 atleast 75% of the time.

In general, the reduced ignition areas or the natural wrapper itself canhave a diffusivity that is relatively low. The diffusivity can bemeasured at room temperature (23° C.). In general, the diffusivity at23° C. of the reduced ignition areas or the diffusivity of the inherentwrapper (without being coated or treated) can be less than about 0.5cm/s, such as less than 0.4 cm/s, such as less than 0.3 cm/s, such asless than 0.1 cm/s, such as less than 0.08 cm/s. In one embodiment, thereduced ignition areas may have a diffusivity of greater than about 0.01cm/s, such as greater than about 0.03 cm/s, such as greater than 0.05cm/s, such as greater than 0.1 cm/s, while still having the desiredreduced ignition proclivity characteristics. Diffusivity is measuredusing a Sodim CO2 diffusivity tester.

While additives may not be necessary in the wrapping material, as thewrapping material according to the present disclosure naturally has goodmanufacturing properties (e.g. tensile strength) and sensory properties,generally, a wrapping material according to the present disclosure mayinclude one or more additives. Additives may be used for manufacturingwrapping papers so as to develop or give the wrapping material newproperties, for instance chemical, optical, sensory or mechanicalproperties such as tear strength or folding resistance. In oneembodiment, an additive may be a humectant, burn control additives, wetstrength agent, an oil-barrier and fat-barrier agent, a antiblockingagent, a dry strength agent, a softener, a flavoring agent, a wettingagent or lattices.

In one embodiment, the web material can further contain a humectant. Thehumectant can be incorporated into the wrapping material for variousdifferent reasons in order to provide different benefits and advantages.For instance, in one embodiment, a humectant may be incorporated intothe wrapping material in order to improve the processability andhandling of the resulting fiber substrate.

While various humectants may be incorporated into the wrapping materialof the present disclosure, humectants may include a polyol, a non-polyolor a mixture thereof. Typically, a polyol generating agent may besorbitol, glycerol, propylene glycol, triethylene glycol or a mixturethereof. Typically, a non-polyol generating agent may be lactic acid,glyceryl diacetate, glyceryl triacetate, triethyl citrate or isopropylmyristate or a mixture thereof. In one embodiment, the humectant isglycerol, propylene glycol, or a mixture of glycerol and propyleneglycol, glycerol being preferred glycerol, propylene glycol, or mixturesthereof. Regardless of the humectant selected, the humectant may bepresent in the wrapping material in an amount of from 0.1% to about 30%by weight of the wrapping material, such as from about 1% to about 10%,such as from about 2% to about 8% by weight of the wrapping material, orany ranges therebetween.

The burn control agent, for instance, may comprise a salt of acarboxylic acid. For example, the burn control agent may comprise analkali metal salt of a carboxylic acid, an alkaline earth metal salt ofa carboxylic acid, or mixtures thereof. Examples of burn control agentsthat may be used include a salt of acetic acid, citric acid, malic acid,lactic acid, tartaric acid, carbonic acid, formic acid, propionic acid,glycolic acid, fumaric acid, oxalic acid, malonic acid, succinic acid,nitric acid, phosphoric acid, or mixtures thereof. Particular burncontrolling agents that may be used include potassium citrate, sodiumcitrate, potassium succinate, sodium succinate, or mixtures thereof.When present, the burn control agent can be applied to the wrappingmaterial generally in an amount greater than about 0.1% by weight, suchas in an amount greater than about 0.5% by weight, such as in an amountgreater than about 1% by weight and generally less than about 5% byweight, such as less than about 4% by weight, such as less than about 3%by weight, such as less than about 2% by weight.

The finished web or wrapper is dried and wound into rolls. For instance,in one embodiment, the dried sheet is wound into bobbins having a widthof from about 15 mm to about 80 mm, such as from about 19 mm to about 28mm. Prior to winding the web into a bobbin, the web may be calendered toincrease the smoothness and runnability of the material. In oneembodiment, for instance, a multi-nip calender device may be used.

These and other modifications and variations to the present inventionmay be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present invention, which ismore particularly set forth in the appended claims. In addition, itshould be understood that aspects of the various embodiments may beinterchanged both in whole or in part. Furthermore, those of ordinaryskill in the art will appreciate that the foregoing description is byway of example only, and is not intended to limit the invention sofurther described in such appended claims.

What is claimed:
 1. A wrapping material for an aerosol producing fillercomprising: a web comprising at least about 40% by weight of anextracted tobacco material, the extracted tobacco material being blendedwith strength building fibers, the strength building fibers comprisingrefined bast fibers, the refined bast fibers having an average fiberlength of less than about 4 mm, the wrapping material having a basisweight of from about 15 gsm to about 45 gsm.
 2. A wrapping material asdefined in claim 1, wherein the web contains the extracted tobaccomaterial in an amount greater than about 50% by weight.
 3. A wrappingmaterial as defined in claim 1, wherein the web has a tensile strengthof greater than about 2,100 cN/30 mm when tested according to ASTM TestD828-97.
 4. A wrapping material as defined in claim 1, wherein therefined bast fibers are present in the web in an amount greater thanabout 10% by weight.
 5. A wrapping material as defined in claim 1,wherein the refined bast fibers comprise refined hemp fibers.
 6. Awrapping material as defined in claim 1, wherein the wrapping materialfurther contains wood pulp fiber in an amount up to about 10% by weight.7. A wrapping material as defined in claim 1, wherein the refined bastfibers have been bleached.
 8. A wrapping material as defined in claim 1,wherein the extracted tobacco material has been refined but has not beenpulped.
 9. A wrapping material as defined in claim 1, wherein theextracted tobacco material contains water soluble components in anamount less than about 20% by weight.
 10. A wrapping material as definedin claim 1, wherein the wrapping material has a basis weight of fromabout 25 gsm to about 38 gsm.
 11. A wrapping material as defined inclaim 1, wherein the wrapping material has a stretch of greater thanabout 1%.
 12. A wrapping material as defined in claim 1, wherein thewrapping material has a permeability of from about 5 Coresta to about 80Coresta.
 13. A wrapping material as defined in claim 1, wherein the webfurther contains filler particles in an amount from about 0.5% to about30% by weight.
 14. A wrapping material as defined in claim 1, whereinthe web contains no filler particles.
 15. A wrapping material as definedin claim 1, wherein the wrapping material has been treated with a burncontrol agent.
 16. A wrapping material as defined in claim 15, whereinthe burn control agent comprises a salt of a carboxylic acid, the burncontrol agent being present in the web in an amount from about 0.3% byweight to about 3% by weight.
 17. A wrapping material as defined inclaim 1, wherein the wrapping material has been treated with a gum. 18.A wrapping material as defined in claim 17, wherein the gum comprisesguar gum, an alginate, carboxymethyl cellulose, or mixtures thereof. 19.A wrapping material as defined in claim 1, wherein the wrapping materialhas a diffusivity of less than about 0.5 cm/s at 23° C.
 20. A wrappingmaterial as defined in claim 19, wherein the wrapping material includesa plurality of reduced ignition areas that have been formed by applyinga reduced ignition composition to the web.
 21. An aerosol generatingproduct comprising: a cylindrical rod comprising an aerosol producingfiller surrounded by the wrapping material of claim 1.